Jeff G 78

Mitchell, that's why I went with 16" wheels, but like Chickenman, I think the OD is too big. When I got my 16" wheels, there were very few good 15" summer tires, but since then, there are actually more on the market. On my race car, I will use 225/45R15 and I might try to switch my street car to 225/45R16 rather than the 225/50R16 tires I currently run. The 205's are just a bit too narrow for my needs.

If you go with a 16x8 or wider, you will likely want to run 225/50R16 tires and they will likely rub both the front and rear fenders. The fronts will rub the front edge of the fender while turning and backing and the rears will rub the fender lips. I'd go with a 15x7 ET0 and run 225/45R50 tires. BFG Rival and Hankook RS3 are both very good and come in that size. If performance isn't as critical, 205/50R15 will fit well too. If you really want 16" wheels, I'd stick with 16x7 and go with 205/50R16 tires. The wider tires will require modifications to combat the rubbing.

I've had good luck with both ATF and 10 wt. motor oil. In my last race, I used ATF and the car accelerated cleanly with very good AFR readings from mid-corner until the end of the straightaways.

I used M5 rivnuts too with custom L brackets that I made.

I'm struggling with this too. I rebuilt my race engine a few years ago and used a ITM gasket set. The pan leaked like crazy even with properly torqued bolts and a flat flange. I pulled the engine to fix a leaky header and redo the oil pan gasket. This time I used a FelPro gasket and again made sure everything was flat and properly sequenced and torqued. Better, but it still leaks a bit. I probably need to pull the engine again since it has some issues from the last race. I'm curious to hear what everybody does for gaskets that stops the leaks once and for good.

Will do. I didn't get a chance yesterday to work in the garage. When I got home I had to take care of a few other things and it was well over 90° in the garage, so I wasn't super motivated after I finished my other things. I should get to it sometime after work this week.

Like others have said, I too would have walked away from it, but I'm sure glad you didn't. The end result is very nice an you will have a beautiful Z for years to come. Congrats on "finishing" it.

Richard, the spark was good and very visible during the day while we were working on it. I only made the night comment because I was surprised how far the spark was jumping. In bright sun I could see it, but I didn't try to jump it as far as I did in the dark. I'm out of town today, but I will at least test a few things tomorrow.

I have had a set since 1986 when I removed them from a '76. Just a few weeks ago I decided to install them on my BRE tribute race car and paint them red and white, but I screwed up and didn't leave the bolts loose enough. Within a few hours, they cracked in several places as the temperature changed. It shouldn't affect them as long as I can find some sort of tape or glue that I can put on the inside to keep the hairline cracks from spreading. When I installed my Lexan hatch and quarter glass, I did it right and they are holding up fine. The heads of the bolts cannot put any clamp load on the plastic. They have to be loose enough to let the plastic expand and contract. If they are available at a reasonable price, I will buy a set and leave them clear for night and rainy races.

I cut the rod and pipe today and roughed out the thrust washer. I need to bore and tap the rod, machine the washer, and weld the washer to the pipe. The puller is very heady duty as is the bearing. I will likely machine a handle that fits the nut since the nut is a 1-5/8" hex and my large adjustable wrench isn't big enough. I might CNC plasma cut several 1/4" plates to fit the nut hex, weld them together and machine/grind them into a comfortable handle. I'll add pics later.

Interesting Richard. Hopefully the crank snout is OK, but at least I have several spare engines to rob parts from if the crank is bad. My biggest worries are the head and pistons since those are P79 and F54 and I don't have any spares of those. I have lots of N47 parts. I did swap the cap and rotor both with and without the new distributor. The spark was pretty sharp and once pitch black outside, I could see it jump over an inch. I will check the crank for runout as you suggest and I will always use red Loctite in the future.

Absolutely correct guys! I have had one of those cars where the pins simply would not come out no matter what. I had to cut mine and even then, the 40 ton press at work was maxed out to get them to budge and eventually press out of the knuckle. Surprisingly, the car in question is completely rust-free. I believe the pins and/or control arms were slightly bent from a rear end hit. Mitchell, I'm curious if the tool failed or the spindle pin threads failed. The tool I am making should never fail and with proper machining of the tool's interface to the spindle pin, I don't think the pin threads will fail either as long as the pin has any chance of removal. Of course, I have not yet proved this theory. I hope to do that soon. I know that no tool will pull every pin, but the tools I have seen and used were not optimized at best and pure junk at worst. I am just trying to build a tool that gives the best chance of pin removal. If I make just one for myself and if works on all pins that can be removed, I will be a happy camper. If I can then supply others with a quality tool, all the better, but my main goal is to make one for myself. I agree the pin design and material is the problem. I also think that it takes a decade or so before they corrode into the knuckle, so as long as the pins are replaced and maintained every few years, I think the Nissan pins will work without redesign. With a good puller, maintenance would be a breeze. The other thing I have never understood was the need for the wedge pin. I see no need for the pin to be kept stationary once the nuts at each end are tightened. I'm convinced that the wedge distorts the steel of the spindle pin and is a large part of the removal woes. Besides that, the wedge hole is likely where some of the moisture gets into the joint. What if the wedge hole is turned into a zerk fitting somehow? I haven't studied it, but maybe there is a way to do it.

It has been a LONG time since I promised that I would build a better mousetrap, but I'm finally getting close to actually building the prototype. I bought the acme rod, nuts and the pipe and I will use a S30 front strut bearing on the first puller. I just need to cut to length and machine the acme rod to accept the spindle pin and weld a large washer onto the pipe for the bearing reaction plate. With any luck, I should have a working tool very soon. If it works as well as I hope, I will make a batch of them and offer them for sale. The cost will need to be fairly high since the materials I'm using are very pricey. I expect the retail cost to be around $75 - $100 depending on the final design. It's not cheap, but if the tool can save the pins, it will pay for itself in pin cost and machine shop labor if the Z owner has to have the pins professionally removed and replaced. Is there anybody who needs to pull their pins soon? I bought enough material to build three prototypes, so once I am happy with the first puller I am willing to sell the next two at the cost of materials only which should be around $50 each in order to get feedback so I can get all the details right..

No and yes Steve. We took the bolt all the way out to inspect it, but we did not remove the damper or try to turn it without the bolt.

Charles, I checked the valve clearances during the prep for the race. The engine had about 16 track hours on it since I last adjusted them and 9 of the 12 were right on and the other 3 were only 0.001" loose. I adjusted them back to spec. The AFR is brand new and worked perfectly throughout the race. The plug readings also looked perfectly light tan, so I'd guess the AFR is accurate.

Hey Steve, I was awaiting your reply. I brought the borescope home from work, so I will at least be able to look down the front cover and in the plug holes. I'll also do a leakdown. With those two tests I should know if it will be a big repair bill or not.

Yeah. Even worse is that we didn't know it was the bolt that was loose. I had a teammate crawl under the car with the 27mm socket and a breaker bar to turn the engine over while I watched the valvetrain. He started turning the bolt and nothing was moving up top. I was sure that the crank had snapped or that something was very broken. I asked him to remove the socket and try turning the bolt by hand. Sure enough, it was backed way out, but once tightened, all looked fine. I have built about a dozen L series engines over the past 35 years and I've never had a crank bolt loosen.

Nice looking muffler!

Great points Zed. As an easy way of telling if the damper is good or bad, I painted a white line across each surface at the timing notch before installing it. If the rubber bond fails, I can easily see if the 2nd row pulley has rotated compared to the first row pulley and center hub. It did not fail as all paint marks are still aligned and they match the timing scale when the keyway is at 12:00. Also agreed on the compression check. I did use the same gauge as always, so the actual readings could be slightly off but they did drop compared to the last time I checked it. I believe my gear set does have the notch, but I am running a very different setup, so I'm not positive if it still applies. I modified the cam gear using eccentric bushings like the "How to Modify..." book describes. My head is shaved 0.050", so to get the timing right, I drilled the cam gear hole and installed offset bushings. I used a degree wheel and dialed in the timing exactly to my cam specs by choosing the correct offset bushing. I did check the bushing and it is still intact and properly positioned. The slack side chain guide as slightly modified to take up the additional slack due to the shorter crank to cam distance. Until I remove the front cover, I won't know for sure, but all looks good at the top of the slack side guide. It is possible the bottom guide bolt loosened allowing the guide to slide in the slot and the chain to go slack. Again, very possible that the spark isn't strong enough since the timing light wouldn't fire through the inductive pickup. I will check the wiring and power to the coil and distributor.

Mark, the initial high RPM misfire was about 5 hours into the race just before a fuel stop. The car progressively got worse (missing at lower and lower RPM) until it finally quit running just after the 6 hour mark. The last 15 minutes were far worse. Prior to that, it still did OK, just had a misfire according to the driver. I was in the car earlier and it ran fine, so I have no direct knowledge of the symptoms. The driver kept reporting that water temp, oil pressure, amps and AFR were normal throughout. We thought it might be vapor lock, so that is why we left him out. In the past, when that happened the symptoms were similar, but there wasn't a quick fix. This time, it was clearly something else since we let it completely cool and it still wouldn't run. The compression check was only done after we checked the easy stuff like fuel, spark, and valvetrain. The puffing was subtle. It almost could have been confused as attempted firing, but it just sounded like the intake charge was being partially expelled. Very tough to call since we were right next to an active race track with lots of background noise.

Pete, that was my #1 theory and it still could be true. I backed-off when I checked the distributor timing and found it to be where it belongs. I will certainly double check it though. Captain, it is certainly possible, though unlikely that both carbs clogged. The fuel flow to the carbs was great. I figured that the starter fluid would rule out a fuel problem, but again, I will revisit everything. Keep the ideas coming. Just because I checked stuff at the track, doesn't mean I won't check again. At this point, I think it's a fun exercise for those of us who have been doing this forever to diagnose the problem. I expected each of you to chime in quickly and there are a few others on the forum that I know will join the fun. It's a frustrating problem, but one that I WILL find the answer to once I fully inspect everything. Hopefully, it's not a catastrophic problem and I only have to replace a woodruff key or a faulty tensioner. Fingers crossed...

I am not ruling anything in or out, but to clarify, here is what I do know: Cliff, the valve springs are all intact and appear good. They are high performance Schneider springs. Phillip, I am with you. I think that the issue is very possibly in the chain guides or tensioner. The top end of the guides looks fine, but until I pull the front cover, I will not know for sure. Pete, I thought that too, but I swapped the entire distributor, so I'm leaning away from that being the issue. I checked the rotation and the lash in the rotor at several positions and all felt correct. Bart, interestingly, I did try to use a timing light to watch for ignition while cranking the engine and it did not work. I will revisit this with another timing light since my advance light gets flaky at times. I have never tried to use a light without the engine running, so I wasn't sure if not getting a light flash meant anything. Again, I swapped the coil, distributor, cap/rotor and wires individually and all together with no change. These are all GREAT suggestions and I would have said exactly the same things if it were me being asked. Keep the ideas coming. I'd love to figure out what happened without needing to tear it all down, but it will likely come to that. I promise I will update the thread as I learn more, though I will not be pulling the engine apart for several months if that's what it comes to. I'm moving the car in November to a new winter home where I have lots of space to work on it over winter. What does everybody think about the low compression and slight puffing? I have run engines (not L Series) a tooth off and they still run fine, just down on power. I would think that if it was off by more that a tooth or two, I would be dangerously close to having piston to valve contact. Oh, one more item that I forgot to mention. While diagnosing, we found that the crank damper bolt was loose by several turns. The engine has 20 race hours on it and the everything was torque checked before this race, so would anything specific cause the bolt to get *impacted* and lose tension? It could have happened when it jumped timing I guess (if the timing jumped).

I'm not necessarily asking for help here, but rather, I'm curious if the armchair Z experts can figure out what is wrong with my race engine. Here is the background... My engine is a F54 block with a shaved P79 head, Web Racing camshaft and a 3-2-1 header. I run SU carbs and a ZX distributor with the E12-80 module. I built the engine a few years ago and it now has two endurance races on it with a total of about 20 race hours. Last weekend we raced the car and the engine was running great with plenty of power. About 6 hours into a 9 hour race it started missing at high RPM just before a fuel stop. We thought it might be a fuel starvation issue, though the AFR never went lean. After the fuel stop, it began to run worse and worse, missing at lower RPM and losing power. The driver radioed in and said that it died and he was coasting into the pits. Oil pressure, water temp, and AFR were all right were they should have been while it was losing power. All of the fuel was bought together and the issues started close to 2 hours into a fuel run, so bad fuel can be ruled out. We began to try different diagnostics, but nothing seemed wrong at first. It had fuel and spark, but wouldn't fire. We thought maybe it had vapor locked, but even after it cooled, it still wouldn't fire. Starter fluid didn't work, so I pulled the plugs and valve cover. The plugs had a perfect light tan color and all of the valves were going up and down with no obvious problems. Next, we checked the ignition timing and valve timing. Both appeared to be correct. With the crank damper mark at #1 TDC, the #1 piston was confirmed to be at TDC and the #1 cam lobes were both up. The distributor rotor was pointing towards #1. I then looked at the cam gear pin with the crank showing TDC and the pin was up where it should be by the naked eye. Next up, the compression was checked. This is where the first problem was found. All 6 cylinders were near 140 PSI with all plugs out and the throttle open. The compression should have been closer to 180 with my engine setup. Again, the engine ran strong earlier in the race. 140 PSI isn't great, but the engine should run reasonably well with 140 PSI if that is the only issue. Next, we tried a different known good coil as well as a known good distributor and module, cap, rotor, and plug wires. We still got no fire. The engine never even tried to start after it initially died on track. Spark was checked at the coil as well as at the plugs and it showed good no matter what ignition parts were used. The fuel lines were removed at the carbs and the electric pump fed plenty of fuel into a pop bottle. We tried bump starting, starter fluid and new ignition parts with no luck. My thinking is that somehow it must be valve timing or valve related due to the low compression readings. It doesn't appear to have skipped timing and the valves appear to go up an down smoothly. The distributor rotor turns as it should and oil pressure was always good, so the crank worm gear and oil pump/distributor shaft do not appear to be stripped. The engine oil and water look fine with no signs of mixed fluids. It could have bent valves, though all six have equal compression and 140 isn't horrible. The engine does appear to puff a bit strangely when cranked, so it feeds the theory of valve timing or bent valves causing the intake charge to escape through the exhaust ports. We also tried to turn the distributor back and forth while cranking. It never sputtered, backfired, or coughed. The engine never made any bad noises while running or when turned over via starter or by hand with a breaker bar and socket on the crank bolt. The engine should not have been money-shifted, but with three drivers, anything is possible. There was only one downshift per lap from 4th to 3rd gear. So... I have not yet done any further diagnostics since getting home, but I will do a leak down and put a borescope in the plug holes within the next week. If I don't see anything, I will pull the engine over the winter and tear it down to check everything. Any theories? Winner gets nothing other than bragging rights and internet accolades. GO!

Like Zed Head said, it might not be as bad as it looks. Rails can be replaced. Find a rear ended Z and have the whole front clip cut off and replaced. It's not an easy job, but it can be done. At least you end up with the same Z. Sorry to see a Z wrecked. Glad you are OK.

Yes, that's a single seam cover. It uses one piece of leather. The three-seam is three smaller, therefore cheaper, pieces of leather. It has a seam at 6 o:clock as well as seams at 2 and 10 o:clock. The cover was still a single color. EDIT: This is interesting. I went to the wheelskins website and clicked on one-color leather. As I went through the four sample colors, the gray, red and blue are single seam, but the black appears to be a three-seam cover. They say nothing about it in the description. http://wheelskins.com/original